In Mass Effect, when you scan the planet Klencory in the Newton system of the Kepler Verge cluster, you get this description:

Klencory is famously claimed by the eccentric volus billionaire Kumun Shol. He claims that a vision of a higher being told him to seek on Klencory the "lost crypts of beings of light." These entities were supposedly created at the dawn of time to protect organic life from synthetic "machine devils." Shol has been excavating on Klencory's toxic surface for two decades, at great expense. No government has valued the world enough to evict his small army of mercenaries.

In Mass Effect 3, the description reads:

Klencory is famously claimed by the eccentric volus billionaire Kumun Shol. His once-ridiculed visions of "beings of light" protecting organic life from synthetic "machine devils" don't seem quite so far-fetched now. His private army of mercenaries are well-established on the planet, waiting for husks to come knocking in on their door. In all likelihood, they will be obliterated by the molten metal of a Reaper orbital bombardment, on its way to somewhere important.